Hasty Briefsbeta

Generating Cats with KPN Filtering

17 days ago
  • #KPN-filtering
  • #generative-modeling
  • #image-generation
  • The post explores generative modeling for cat images using KPN denoising in pixel space.
  • Unlike typical diffusion models operating in latent space, this approach uses KPN bilateral filters and predicts low-rank targets directly.
  • KPN filters offer good regularization bias and efficient GPU implementation, suitable for edge devices.
  • The model is trained on 64x64 cat images, using an architecture with an 8x8 patch transformer and upscaling convolutions.
  • Training involves gradually noising images to Gaussian noise and predicting the original using L2 and LPIPS losses.
  • Bilateral filters' convex combination limitation is mitigated by a low-capacity network predicting color drift (bias) added post-filtering.
  • Non-convex filtering is enabled by not normalizing bilateral weights and using tanh activation, allowing new color/detail generation.
  • A simplified version of Neural Partitioning Pyramids and Procedural Kernel Networks optimizes the filtering network.
  • Color drift prediction uses a small U-Net for low-frequency components, improving color fidelity while KPN filtering can be quantized.
  • Generated samples after 5k epochs serve as a proof of concept, though results are not yet impressive.